Which idea was once accepted is now considered a scientifically inaccurate
a. tge nucleus is the center of the atom
b. an atom is solid material
c. electrons have a negative charge
d. electrons are arranged in layers

Using a value of ksp = 1.8 x 10-2 for the reaction pbcl2 pb+2(aq) + 2cl -(aq). if the value of ksp was determined to be only 1.2 x 10-2: too much solid has dissolved. additional precipitate is forming. the solution is unsaturated. the ions are now combining to reduce their concentrations.

Aglow stick contains a glass vial with chemicals. when the glow stick is bent, the vial breaks and the chemicals react to produce a glow. a science student observes that a glow stick kept in the freezer glows for a longer duration than a glow stick kept at room temperature. what conclusion can be drawn based on the observation? be sure to note the outcome and test variables in the conclusion.

How many grams of oxygen gas are contained in a 15 l sample at 1.02 atm and 28°c? show your work.